Slack adjuster



June 23, 1953 QOBINS'QN 2,642,963

SLACK ADJUSTER Filed Oct. 14, 1946 s Sheets-Sheet 1 INVENTOR. JOSEPHRoam/sou J. ROBINSON SLACK ADJUSTER June 23, 1953 5 Sheets-Sheet 2 Filed001;. 14,;946

I N V EN TOR. J0 SEPH Ros/-50 HTTOIPAE June 23, 1953 J. ROBINSON SLACKADJUSTER 5 Sheets-Sheet 4 Filed Oct. 1 4, 1946 QNfiE R O ww 3v 3w m msa?! fi f a 0 v hm P0 M m. w mm. Z w m M w H ,fl w n, V- B um ,o $.w f I%ww J. ROBINSON June 23, 1953 SLACK ADJUSTER 5 Sheets-Sheet 5 Filed Oct.14, 1946 INVENTOR. JOSEPH Roam/sou Patented June 23, 1953 UNITED STATESPATENT OFFICE SLACK ADJUSTER Joseph Robinson, New York, N. Y.Application October 14, 1946, Serial No. 703,258 2 Claims. (01. 188-197)This invention relates to'slack adjusters for removing undesired slackin the brake rigging of railway cars due to brake shoe wear. It is animprovement on the slack adjuster shown in my United States Patent#2,190,681, granted Febru ary 20, 1940. A primary object is to provide asimple and compact adjuster which by a simple "pull and let go operationinstantly takes up the brake shoe slack at either or both ends of thecar, and which can be re-set without workmen having to go under the caror between the ends of opposing cars. Other objects and advantages of myimprovement are described in the following specification, pointed out inthe appended claims and illustrated in the accompanying drawings inwhich:

Figure 1 is a small scale plan View of a typical application of myimproved slack adjuster to the brake cylinder and brake rigging of acar;

Figure 2 is a small scale plan view, similar to Figure 1, showing atypical application of my improved slack adjuster to the center sill ofa car;

Figure 3 is an enlarged side elevation of my improvement and a part ofthe brake cylinder shown in Figure l, the adjustment lever C and therelease rod G being shown in section;

Figure 4 is a top view of the construction shown in Figure 3 with a partof the member 21 broken away;

Figure 5 is a bottom view of the construction shown in Figure 4; Figure6 is a sectional detail taken on approximately the line 6-45 of Figure3;

Figure '7 is a rear view of the construction shown in Figure 3. In-thisView a part of the brake cylinder is broken away, and the adjustmentlever C and the release rod G are shown in elevation;

Figure 8 is a detail in. elevation showing the pivoted link F at thelimit of its rearward swing, and the ratchet bar E at the moment ofinitial adjustment Figure 9 is a view similar to Figure 8 showing theratchet bar and link in the position they assume when the :bar movesthrough the link for adjustment, and

Figure 10 is a sectional elevation of the construction shown in Figures8 and 9 with the ratchet bar in one of its adjusted positions andinterlocked with the link F preparatory to swinging the link forward tothe limit of its movement.

Referring to the drawingsz-In Figure 1 my improved slack adjuster A isshown attached to the rear end of a conventional air brake cylinder B. Ageneral arrangement of the brake rigging, or foundation brake equipment,operated by my immovement is schematically indicated in this view, andbrackets ll, l2 and M are shown for supporting parts of the brakeequipment. The ends l5, l6 and I! of the brackets serve as stops forlimiting the movement of the levers C-D each of which, as shown, isoperatively connected with the brake rigging of the car. The brakerigging includes transversely arranged suitably supported brake beams,not shown, which are provided with :brake shoes that are drawn againstthe periphery of the car wheels, not shown, when levers C and D areactuated by the piston within the cylinder 13, Figure 1. Thisarrangement is generally indicated in Figure 1 of my aforesaid UnitedStates Patent #2,190,681 in which 23 designates a brake shoe headcarried at one end of a brake beam in the brake rigging of the car.Normally a predetermined amount of clearance or free slack, usuallyabout 2%", is maintained between the brake shoes and the car Wheelscollectively when the brakes are in the releasedposition. How thisclearance or free slack is provided and maintained with the presentinvention will appear hereinafter.

If the cylinder B is not provided with the usual attachment lug l8,Figure 3, any suitable substitute for it may be employed. To this lug orto its substitute my improved slack adjuster A is suitably anchored asby means of bolts l9. Immunity to the serious operational difficultiesexperienced with present types of slack adjusters due to theaccumulation therein of foreign matter, such as snow and ice, iseffectively obtained by constructing the body or housing of myimprovement in the form of a frame comprising the member or cover plate2 I preferably U-shaped in cross section to stiffen it and to span theattachment lug l8, Figures 4 and 6, and a pair of laterally spacedhorizontally disposed carrier irons 22 having any desired crosssectional form. The rear ends of these irons are upwardly turned at 23,-Figure 3, and pass through the member 2| and are riveted thereto at 24,or are otherwise suitably secured thereto. The front ends 25 of theirons are widened and are ofiset downwardly to engage with theattachment lug I8, Figure 3, the lug serving also to space the frontends of the irons with respect to the plate 2|. Bolts I9, or othersuitable securing means, rigidly anchor the front end of the plate 2|and the carrier irons 22 together as well as to the attachment I8 on thecylinder B. A spanner 26 through which the bolts l9 pass embraces thefront ends of the the upwardly turned rear ends 23 of the irons servingas stops for limiting the reaward travel of the lever. Between theseirons and below the plate 2| I mount a ratchet bar E having a pluralityof rugged teeth 21. The front end of the bar is forked at 28 to receivethe pivotally anchored thereto by the pin 29, the pin being insertedthrough the opening 39, Figures 3 and 4, in the plate 2|. The ratchetbar E extends rearwardly from a point immediately behind the cylinder Bto a point beyond the rear ends of the carrier irons 22 and passesloosely through the opening 3|, Figure 8 in the pivot or adjustment linkF. The link is provided at the bottom of its opening with a heavy lug ortooth 32 which meshes or interlocks with the teeth 21 of the ratchet barE. A fiat bearing surface 33, Figure 8, formed on the upper rear wall ofthe opening 3| in the link engages the fiat top of the ratchet bar andcoacts with teeth 2l--32, Figure 3, to powerfully lock the bar againstforward movement in the link F from any of its service positions. Thelink spans and is pivoted in any desired way, as by the pin 34, Figures'7 and 8, to a vertically disposed lug 35 suitably arranged on the rearend of the plate 21 and extending rearwardly thereof and of the carrierirons 22. To prevent undesired extraction of the ratchet bar from thelink F, and

under certain conditions to swing the link forward to the limit of itsmovement, a stop device 36, Figures 3, 5 and '7, is removably mounted inor on the rear end of the bar by suitable means such as the cotter pin31.

When the brake rigging of the car is in the normal released position, acertain amount of clearance or slack is, of course, necessary betweenthe rim of the car wheels and the brake shoe. To provide this clearanceor slack the link F is free to pivot or swing forward on its pivot pin34 from the position shown in Figures 8, 9 and 10 to the position shownin Fig. 3, the extent of this movement being such as to provide thedesired free slack. Forward swing of the link is limited by engagementof its upwardly extending projection 38 with the bearing 39 on the lug35, whilst rearward swing of the link is limited by engagement of itsprojection 38 with the finger or stop 40 of the lug, Figures 3, 8, 9 and10. When the link reaches the limit of its rearward movement, Figures8-1.0, its inclined face 4| assumes approximately a horizontal positionat which time the interlock of the ratchet bar E with the link F, Figure8, is released and the bar is free to rise in the opening 3| in the linkand slide rearwardly over the tooth 32. While the link F is in thisrearward position the rear face 42 of its tooth, Figure 9, is at aforward angle to the vertical. The arrangement facilitates movement ofthe bar E forward in the link F from the position shown in Figure 10,for instance, to the position shown in Figure 8. This movement of thebar is made when it is desired to replaceworn out brake shoes and re-setmy improved slack adjuster to the initial service position shown inleverC and-is Figures 1, 2 and 3. The re-setting is accomplished by movingthe link F, through the medium of the lever C, Figures 1 to 5, to thelimit of the rearward movement of the link, Figures 8, 9 and 10, and byretaining it in that position by means of the rotatable release rod G,Figures 1 to 5 and '7 and 10. This is accomplished by providing the linkF with an integral laterally extending projection 43, Figures 3, 4, 5and 7, against which the arm 44 of the release rod G engages to hold thelink at the limit of its rearward movement, Figure 10, when the handle45, Figure '7, of the rod is manually rotated to the left to its fullextent. The rod extends through and is supported by a bracket H, Figures1, 2 and 7, which is suitably attached to the car body, the rod beingrotated in the bracket by the aforesaid handle 45. The arm 44 passesdown through the opening 46, Figure 7, in the head 41 of the pin 34, andis removably retained therein by a cotter pin 48.

The adjustment lever C, and the release rod G extend horizontally frommy improved slack ad-. juster to a point approximately flush with theside of the car making it unnecessary for a workman to go under orbetween the cars to operate or re-set. To take slack with my improvementit is only necessary to push or pull to the left, Figures 1, 2 and 3, onthe handle 49 of the lever C as far as it will travel, then let go. Thefirst effect of this is to swing the link F to the position shown inFigures 8, 9 and 10, and the next effect is to cause the ratchet bar Eto slide through the link F to the extent of any slack that may exist inthe brake rigging due to brake shoe wear. Immediately the push or pullon the lever is released, one of the teeth 2'! of the bar E will dropinto interlocked engagement with the tooth or lug 32 of the link. Thebar and the link will then swing forward until the link engages itsbearing 39 of the lug 35, Figure 3, thereby establishing the desiredfree slack. To replace worn out brake shoes the lever C is pulled orpushed to the left as far as it will go. This swings the link F to theposition shown in Figures 8, 9, and 10. Withone hand the operator holdsthe link in this position through the medium of the release lever G andits handle 45, Figure 10, and with the other hand he shoves the lever Cforward to the limit of its forward movement, which is to say to theposition shown in Figure 3. During this operation the stop 36 on theratchet bar E engages the back of the link F and swings the link forwardto the limit of its forward movement shown also in Figure 3 and intointerlocked engagement with the ratchet bar E. This simple operationre-sets my improved slack adjuster for easy removal and replacement ofworn out brake shoes, proper free slack or clearance for the new shoesbeing established by the forward wing of the link F from the positionshown in Figure 8 to the position shown in Figure 3. The compactness ofmy improved slack adjuster gives it a short overall length. Inconsequence, support from the car body for the rear end of the adjusterhas not been found necessary, but I show for this purpose a suitablebracket 50 secured to the lug 35 by a rivet or other means 5| andattached to the car in any way desired. The construction of theessential parts of my improvement is the same whether it is attached tothe brake cylinder B, Figures 1 and 3, or to a part of the car body, asin Figure 2. For this reason I have referred broadly herein to the lugIt as an attachment and have so numbered the attachment bracket l8 inFigure 2,

What I claim is:

1. A slack adjuster comprising, in combination, with a brake cylinder,an attachment lug on the brake cylinder, a pair of parallel horizontallyarranged carrier irons secured at one end to the attachment lug andturned upwardly at the opposite end, an elongated cover plate riveted atone end to the upwardly turned ends of the said carrier irons anddetachably secured at th opposite end to the upper side of theattachment lug thereby providing a frame to protect the slack adjusterfrom accumulation of foreign matter thereupon, a bracket securing theend of the frame remote from the attachment lug to the car, anadjustment lever supported by said carrier irons and operably disposedbetween the carrier irons and the elongated cover plate, said adjustmentlever being connected with the brake rigging of the car and extendinghorizontally across the longitudinal axis of said adjuster through saidframe to a point adjacent the side of the car, a link pivoted on saidframe and disposed at the opposite end thereof relative to theattachment lug beyond the bracket and a ratchet bar pivoted to saidadjustment lever and adjustably engageable with said link forcooperating with the link to remove undesired slack in said brakerigging at either or both ends 01' the car when the link is swung to thelimit of its movement in one direction and to preserve desired slacktherein at either or both ends of the car when the link is swung to thelimit of its movement in the opposite direction.

2. A slack adjuster as described in claim 1, wherein means are providedfor holding said link at the limit or its rear movement while theratchet bar is moved forward in the link to reset said slack adjuster,said resetting being accomplished from a position adjacent the side ofthe car.

JOSEPH ROBINSON.

References Cited in the file of this patent UNITED STATES PATENTS

